Описание
In the Linux kernel, the following vulnerability has been resolved:
ALSA: bcd2000: Fix race between rawmidi and disconnect
Although we tried to fix the potential UAF issues at USB disconnect on
bcd2000 driver, there is still an overlooked case -- namely, when a
rawmidi trigger callback has been already running at USB disconnect
handling, the in-flight function (e.g. bcd2000_midi_send()) could
still access the URB, because the previous URB NULL-check & clearance
was considered only for the URB complete callbacks, but not about the
parallel rawmidi operations.
For addressing the race, this patch introduced a new spinlock that
covers each rawmidi operation as well as the rawmidi handling in the
complete callback. The URB is cleared with the lock, so it guarantees
that the pending rawmidi task already finished or a NULL check is
effective.
A flaw was found in the Linux kernel's ALSA bcd2000 driver. This vulnerability allows a local user to cause a Denial of Service (DoS) by crashing the system. A race condition exists between ongoing MIDI data processing and USB device disconnection, allowing active tasks to access memory after it has been freed. By disconnecting the device during active data transfer, a user can trigger this use-after-free flaw to crash the operating system.
Отчет
This vulnerability is rated as a Moderate severity impact because triggering the race condition requires local access, precise timing during device removal, and the presence of Behringer BCD2000 USB hardware or an emulated USB device. Typical Red Hat Enterprise Linux deployments do not attach or use this specialized DJ controller, significantly limiting exposure on standard server and cloud installations. Even if an attacker has the necessary local access to initiate MIDI communication, the resulting blast radius is constrained to a local denial of service via a kernel crash.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred |
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Дополнительная информация
Статус:
EPSS
7 High
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: ALSA: bcd2000: Fix race between rawmidi and disconnect Although we tried to fix the potential UAF issues at USB disconnect on bcd2000 driver, there is still an overlooked case -- namely, when a rawmidi trigger callback has been already running at USB disconnect handling, the in-flight function (e.g. bcd2000_midi_send()) could still access the URB, because the previous URB NULL-check & clearance was considered only for the URB complete callbacks, but not about the parallel rawmidi operations. For addressing the race, this patch introduced a new spinlock that covers each rawmidi operation as well as the rawmidi handling in the complete callback. The URB is cleared with the lock, so it guarantees that the pending rawmidi task already finished or a NULL check is effective.
In the Linux kernel, the following vulnerability has been resolved: ALSA: bcd2000: Fix race between rawmidi and disconnect Although we tried to fix the potential UAF issues at USB disconnect on bcd2000 driver, there is still an overlooked case -- namely, when a rawmidi trigger callback has been already running at USB disconnect handling, the in-flight function (e.g. bcd2000_midi_send()) could still access the URB, because the previous URB NULL-check & clearance was considered only for the URB complete callbacks, but not about the parallel rawmidi operations. For addressing the race, this patch introduced a new spinlock that covers each rawmidi operation as well as the rawmidi handling in the complete callback. The URB is cleared with the lock, so it guarantees that the pending rawmidi task already finished or a NULL check is effective.
ALSA: bcd2000: Fix race between rawmidi and disconnect
In the Linux kernel, the following vulnerability has been resolved: A ...
In the Linux kernel, the following vulnerability has been resolved: ALSA: bcd2000: Fix race between rawmidi and disconnect Although we tried to fix the potential UAF issues at USB disconnect on bcd2000 driver, there is still an overlooked case -- namely, when a rawmidi trigger callback has been already running at USB disconnect handling, the in-flight function (e.g. bcd2000_midi_send()) could still access the URB, because the previous URB NULL-check & clearance was considered only for the URB complete callbacks, but not about the parallel rawmidi operations. For addressing the race, this patch introduced a new spinlock that covers each rawmidi operation as well as the rawmidi handling in the complete callback. The URB is cleared with the lock, so it guarantees that the pending rawmidi task already finished or a NULL check is effective.
EPSS
7 High
CVSS3